Primarily because of the expense of the precious metals used in the fabrication of electronic components such as printed circuits and the like, extensive efforts have been made in recent years to confine the amount of plating metals used to the precise areas required and to recover plating solution for reutilization. In addition, there has been a need for plating on a continuous basis so as to reduce the time involved in the fabrication of micro-circuitry and, in as much as plating is one phase in the fabrication process which has not been susceptible to operation on a continuous basis, to provide continuous spot plating and thereby to appreciably reduce the overall amount of handling and processing time involved as compared with plating on a batch treatment basis.
Although strip plating on a continuous basis is known as shown in U.S. Pat. Nos. 4,431,550, 4,452,684 and 4,610,722, so far as the applicant is aware, effective apparatus for continuous spot plating on a moving substrate is unknown in the prior art.